CORRELATION BETWEEN WATER QUALITY AND Chl.a OF PHYTOPLANKTON AND THE COUNTERMEASURES FOR INHIBITING ALGAL GROWTH IN WEST LAKE, HANGZHOU

On the basis of the analysis of chlorophyll-a and physicochemical factors in the water of West Lake, the results show that algal growth in Lake Beili, Lake Yue, Lake Xili and Lake Wai is affected mainly by water temperature, and is not limited by the high concentrations of N and P in the water. The water quality in L.Xiaonan is better than that in other lake areas, because it lies at the diversion entrance and is directly influenced by drawing water from Qiantang River. Studies on biological control experiments suggested that a reasonable and coordinated ecological system would be more beneficial to the water quality than the other countermeasures.Article信州大学理学部附属諏訪臨湖実験所報告 11: 29-34(1999)departmental bulletin pape

STUDY ON THE CORRELATION OF WATER QUALITY FACTORS WITH SPECIES DISTRIBUTION OF MANGANESE IN WEST LAKE

In this paper, changes in water quality factors of West Lake and variations in the speciation distribution of Manganese in both water and bottom sediment from June 1995 to May 1996 was reported. The correlation of manganese species distribution with water quality factors was also investigated. The results showed that besides TP, T, TIN, and chl-a etc., Manganese was also one of the main factors which affects water transparency.Article信州大学理学部附属諏訪臨湖実験所報告 11: 73-77(1999)departmental bulletin pape

Hybrid precoding for beamspace MIMO systems with sub-connected switches: a machine learning approach

By employing lens antenna arrays, the number of radio frequency (RF) chains in millimeter-wave (mmWave) communications can be significantly reduced. However, most existing studies consider the phase shifters (PSs) as the main components of the analog beamformer, which may result in a significant loss of energy efficiency (EE). In this paper, we propose a switch selecting network to solve this issue, where the analog part of the beamspace MIMO system is realized by a sub-connected switch selecting network rather than the PS network. Based on the proposed architecture and inspired by the cross-entropy (CE) optimization developed in machine learning, an optimal hybrid cross-entropy (HCE)-based hybrid precoding scheme is designed to maximize the achievable sum rate, where the probability distribution of the hybrid precoder is updated by minimizing CE with unadjusted probabilities and smoothing constant. Simulation results show that the proposed HCE-based hybrid precoding can not only effectively achieve the satisfied sum-rate, but also outperform the PSs schemes concerning energy efficiency

DYNAMIC VARIATION OF WATER QUALITY IN WEST LAKE AND MULTIVARIATE ANALYSIS OF ITS PRIMARY FACTORS

Dynamic variation of water quality in West Lake is analyzed based on the data of 1995. Principal Component Analysis is used to reveal the mutual relationships of various factors. It is shown that there exists an obvious special and temporal variation in the main factors of water quality. Annual values of TP, TN, and Chl.a fluctuate seasonally. In addition, Chl.a has a synchronous variation with water temperature, although being lagged a little, and closely relates to TP and TN. SD has a good negative relation with Chl.a. The results from Principal Component Analysis show that SD, Ec, Tw, pH and Chl.a are the most influential factors in water quality of the West Lake.Article信州大学理学部附属諏訪臨湖実験所報告 11: 21-27(1999)departmental bulletin pape

Ultra-wide band signal generation using a coupling-tunable silicon microring resonator

International audienceUltra-wide band signal generation using a silicon microring resonator tuned to an NRZ-DPSK modulated optical carrier is proposed and demonstrated. The scheme is shown to enable the generation of UWB signals with switchable polarity and tunable bandwidth by simply tuning the coupling regions of the microring resonator. Monocycle pulses with both negative and positive polarities are successfully synthesized experimentally

A CIRCULATION DYNAMICS MODEL IN THE ECOSYSTEM FOR THE WEST LAKE, HANGZHOU

This paper focuses the researches on an eutrophication model after drainage of wastewater and drawing water from the Qiantang River to West Lake. The model describes the circulation of nutritive matters (such as phosphorus, nitrogen, and carbon) in the ecosystem of the Lake. The model was established according to observed values of water quality and relevant parameters in 1995. The results of model calibration and verification show that the model can reasonably respond to the changes of forcing functions for drawing quantity and temperature of water. The model has been used to forecast the water quality in different drawing quantities. The predictions given by the model are also believed to be useful to comprehensively harness the West Lake.Article信州大学理学部附属諏訪臨湖実験所報告 11: 87-98(1999)departmental bulletin pape

A Moving Source Localization Method for Distributed Passive Sensor Using TDOA and FDOA Measurements

The conventional moving source localization methods are based on centralized sensors. This paper presents a moving source localization method for distributed passive sensors using TDOA and FDOA measurements. The novel method firstly uses the steepest descent algorithm to obtain a proper initial value of source position and velocity. Then, the coarse location estimation is obtained by maximum likelihood estimation (MLE). Finally, more accurate location estimation is achieved by subtracting theoretical bias, which is approximated by the actual bias using the estimated source location and noisy data measurement. Both theoretical analysis and simulations show that the theoretical bias always meets the actual bias when the noise level is small, and the proposed method can reduce the bias effectively while keeping the same root mean square error (RMSE) with the original MLE and Taylor-series method. Meanwhile, it is less sensitive to the initial guess and attains the CRLB under Gaussian TDOA and FDOA noise at a moderate noise level before the thresholding effect occurs

Petroleum resource assessment of the East Greenland Basin

The onshore and offshore parts of the East Greenland Basin are important areas for petroleum exploration at the North Pole. Although assessments by the US Geological Survey suggest a substantial petroleum potential in this area, their estimates carry a high risk because of uncertainties in the exploration data. This paper compares the reservoir-forming conditions based on data from the East Greenland Basin and the North Sea Basin. The petroleum resources of the East Greenland Basin were assessed by geochemical and analogy methods. The East Greenland Basin was a rift basin in the late Paleozoic–Mesozoic. Its basement is metamorphic rock formed by the Caledonian Orogeny in the Archean to Late Ordovician. In the basin, Devonian–Paleogene strata were deposited on the basement. Lacustrine source rock formed in the late Paleozoic and marine source rocks in the Late Jurassic. Shallow-marine sandstone reservoirs formed in the Middle Jurassic and deep-marine turbiditic sandstone reservoirs formed in the Cretaceous. The trap types are structure traps, horst and fault-block traps, salt structure traps, and stratigraphic traps. The East Greenland Basin possesses superior reservoir-forming conditions, favorable petroleum potential and preferable exploration prospects. Because of the lack of exploration data, further evaluation of the favorable types of traps, essential amount of source rock, petroleum-generation conditions and appropriate burial histories in the East Greenland Basin are required